Mitigation of earthquake-induced pounding effects on adjacent reinforced concrete buildings

Pounding effect is one of the most common causes for the seismic damages observed in adjacent reinforced concrete (RC) buildings during past earthquakes. This study aims to minimize seismic damage caused by pounding on existing RC structural elements in cases where collision is unavoidable. For this purpose, the pounding effects are investigated by using 4- and 7-story RC buildings. To protect the existing RC column elements from pounding effects, steel I-profile columns are placed in the infill wall and pounding was ensured in these elements instead of existing RC columns. In addition, neoprene rubber pads are placed on the steel I-profile columns to provide additional energy damping during the collision. Nonlinear response history analyses are performed using 11-different real ground-motion records. Parameters such as absolute peak floor accelerations, inter-story drift ratios, link forces, story shear force distributions, and plastic hinge distributions are recorded and compared for each of the pounding conditions. Different nonlinear force-displacement relations are considered in the definition of gap elements to compare the effect of gap element modeling options on the analysis results. For these response parameters, each force-displacement relation defined for different gap elements are examined individually. The analysis results show that the damaging effects of pounding could be reduced with the additional steel I profile column and neoprene rubber pad to be placed in existing reinforced concrete buildings.